Representational forms of data and data structures are often displayed to a user via a user interface. The forms of the data are “representational” in the sense that data is typically stored in various forms of memory as one or more series of binary signals in electrical and magnetic storage devices, but may be translated into characters (representations), often alphanumeric, comprehensible by users interacting with them. A data structure is a particular way of organizing and storing data in a computer so that it may be used efficiently. Common data structures include arrays, linked lists, tables (e.g., hash-tables), heaps, trees, stacks, and queues.
It is common to use tree structures to represent hierarchical information in software applications, such file folders, database relations, software code class trees, system registries, etc. Such tree structures facilitate access to information by organizing the information in a logical manner. However, as the information to be organized becomes larger and more complex, containing more nodes and more levels in the hierarchy, it becomes difficult to navigate through these levels.
For example, a database typically takes advantage of a tree structure as databases are often administered in a hierarchical manner. Such a tree structure contains a number of (dominant) items, and each item may have an arbitrary number of (subordinate) items. Several interrelated items will typically be grouped under a single dominant item. Subordinate items may be dominant to and contain subordinate items of their own.
In known graphical user interfaces (GUIs), tree views have received wide acceptance for allowing a user the ability to transverse hierarchal data structures (branch objects), and to display an object's content (leaf object). The tree view has a wide acceptance in many software applications, although tree views present a number of usability limitations. Typically, navigating the tree structure is a rather arduous and manual process. To proceed from one location to the next, the user must often expand and/or collapse numerous branches within the tree structure. Furthermore, a tree view only displays the content of a single object at a time.